The present invention relates to a functional protective material, in particular with protective functions with regard to chemical and/or biological poisons and/or noxiants, which has a multilayered construction and contains a membrane, in particular for use in a protective apparel, with the features set out herein.
The present invention further relates to a membrane for use in a functional protective material of this type, as classified herein.
The present invention further relates to the use of the inventive protective material and/or membrane as defined herein and also to protective articles as defined below, which were obtained using the inventive protective material and/or membrane.
The present invention additionally relates to the use of the inventive protective material and/or membrane in the manufacture of protective materials of any kind (such as, for example, protective suits, protective gloves, protective shoes and other protective apparel pieces and also protective covers, for example for medical transports, tents, sleeping bags and the like).
The present invention finally relates to protective articles comprising the inventive protective material and/or membrane and/or obtained using the inventive protective material and/or membrane. The inventive protective material and/or membrane are thus useful not only for the military sector but also for the civil sector, in particular for NBC deployment.
There are a series of substances which are taken up by the skin and lead to serious physical harm (noxae). Examples include the vesicatory Hd (interchangeably referred to as Yellow Cross and mustard gas) and the nerve agent sarin. People likely to come into contact with such poisons must wear suitable protective apparel and/or be protected against these poisons by suitable protective materials. In addition, people likely to come into contact with other toxic substances also need to be protected through appropriate protective apparel and/or materials.
Protective apparel and/or materials known for this purpose include for example air and water vapor impervious protective suits equipped with a rubber layer impervious to chemical poisons. These suits are disadvantageous in that they very quickly lead to a heat build-up, since they are air and water vapor impervious. Other disadvantages here include the nonexistent breathability and also the nonexistent exchange of air.
Protective suits against chemical warfare agents that are intended for prolonged deployment under a very wide variety of conditions, however, must not lead to a heat build-up for the wearer. To this end, air and water vapor pervious protective suits are known in the prior art, which offer a relatively high wearing comfort. Air and water vapor pervious protective suits of this type often possess an adsorptive filtering layer of activated carbon to permanently bind the chemical poisons. The advantage of systems of this type is that the activated carbon is also accessible on the inside surface, ensuring rapid adsorption of poisons which have penetrated at damaged or otherwise nontight places. Under extreme conditions, in particular when a drop of a thickened poisonous or warfare agent lands on the protective suit material from a comparatively great height and strikes through to the activated carbon, however, the layer of activated carbon can be locally inadequate. In addition, the protective performance which protective suits of this type offer in respect of biological noxiants is often also inadequate.
Permeable, adsorptive filtering systems, in particular those based on activated carbon, are therefore often additized with a catalytically active component by impregnating the activated carbon for example with a biocidal and/or biostatic catalyst, in particular one based on metals or metal compounds.
A protective material of this type is described for example in DE 195 19 869 A1, which contains a multi-ply, textile, gas-pervious filtering material comprising an adsorption layer based on activated carbon, more particularly in the form of carbonized fibers, the activated carbon being impregnated with a catalyst selected from the group consisting of copper, cadmium, platinum, palladium, mercury and zinc, in amounts ranging from 0.05% to 12% by weight, based on the activated-carbon material. The disadvantage with this protective material and/or filtering system is the fact that impregnation with the catalyst destroys a portion of the adsorption capacity needed for adsorbing and thus disarming chemical noxiants. The impregnating operation thus has an adverse impact on the performance capability of the activated carbon used. Furthermore, impregnating the activated-carbon material is relatively costly and inconvenient and often compromises the manufacturing operation for the activated carbon, more particularly the activating step. Moreover, impregnation with the catalyst does not always provide the desired efficacy with regard to biological noxiants and/or microorganisms, and the problem of poisonous or warfare agents striking through at high concentrations is not always solved by this principle. Finally, the impregnating operation requires relatively large amounts of the catalyst material.
The prior art further includes protective suits engineered to be air impervious yet water vapor pervious, or breathable. Protective suits of this type generally comprise a membrane that acts as an air impervious yet water vapor pervious or breathable blocking layer with regard to poisonous and/or warfare agents. However, protective suits comprising membrane systems of this type do not always deliver an adequate protective performance. In addition, the protective membranes often used in this context in the prior art as blocking-layer membranes of this type do not always ensure adequate breathability, especially not under deployment conditions involving physical exertion, and therefore the wearing comfort is occasionally compromised as a consequence of the lack of air exchange and/or the lack of emission of water vapor through the protective material. In addition, protective materials used in the prior art may also comprise a microporous membrane. Membrane systems of this type generally do have an elevated ability to transmit water vapor, but also have the disadvantage that the pores in the microporous membrane system may occasionally be pervious to small molecules in particular, including for example the toxic substances hydrogen cyanide and chlorine gas. Membrane systems of this type are thus not always able to provide effective protection against noxiants and/or poisons in the form of small (gas) molecules in particular.
The problem area mentioned above was already recognized and addressed in the prior art from which the present invention proceeds (WO 2009/086858 A1). According to its solution, the membrane, which is inherently air and water vapor pervious by virtue of its having for this purpose a multiplicity of micropores distributed essentially uniformly over the membrane area, is endowed with a reactive additization, especially with a catalytically active component possessing reactivity with regard to chemical and/or biological poisons and/or noxiants. As a result, the multilayered functional protective material additized with a membrane of this type delivers an improved protective performance with regard to chemical and/or biological poisons/noxiants. This additization of the membrane ensures that poisonous/noxiant agents are degraded before they can come into contact with any adsorptive layer.
Yet even a thus additized membrane of a functional protective material of this type still presents a problem because the membrane is inherently pervious to air and water vapor and should also be so on account of the wearing comfort. Deployment by a user, then, may give rise to the situation that, for example, organic substances such as splashes of vehicle motor fuels landing on the functional protective material in the course of the refueling of motor vehicles pass through the micropores in the membrane and saturate the adsorptive material situated thereunder in the construction. In the later incidence of biological poisons and noxiants, such as warfare agents, the adsorptive material is then ineffective at this location.
In a previous attempt to solve this problem, a protective apparel composed of a corresponding protective material is additionally assigned an outer shell (DE 20 2009 004 718 U1). But this is very inconvenient in practice.